1. Technical Field
The present invention relates to the field of driver assistance systems (DAS) and in particular to detection of obstacles in a road using a camera.
2. Description of Related Art
Larson et al. [1] perform detection of negative obstacles using LIDAR and other three dimensional data. Belutta et al. [2] detect depth discontinuities of negative obstacles from stereo range data. Rabkin et al. [3] use stereo range data on thermal cameras because the shape of the terrain also affects the thermal properties. Muraka et al. [4] combine stereo and motion information to detect discontinuities in daytime. They assume a piecewise planar model and show results from indoor and outdoor environment. The range of detection of drop-offs is limited to a few meters since texture is required for stereo and motion correspondence. Witus et al. [5] analyze the shadows produced by light sources mounted on the host vehicle using a stereo camera. Detection range is limited by camera focal length and stereo baseline. Furthermore, depth information on the shadow edge is only available when the light sources are displaced along the stereo baseline. In contrast, a typical stereo camera for driver assistance applications has the two cameras mounted side by side and the headlights are below the cameras.
References
                1. Larson et al., “Lidar based off-road negative obstacle detection and analysis” In 14th International IEEE Conference on Intelligent Transportation Systems (ITSC), October 2011        2. Belutta et al., “Terrain Perception for Demo III”, In Proceedings of the IEEE Intelligent Vehicles Symposium (IV) 2000, October 2000        3. Rabkin et al. “Nighttime negative obstacle detection for off-road autonomous navigation In Unmanned Systems”, Technology IX. Edited by Gerhart, Grant R.; Gage, Douglas W.; Shoemaker, Charles M. Proceedings of the SPIE, Volume 6561, pp. 656103 (2007)        4. Muraka “Detecting obstacles and drop-offs using stereo and motion cues for safe local motion”, In IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2008 September 2008        5. Witus et al. Preliminary investigation into the use of stereo illumination to enhance mobile robot terrain perception In Proc. SPIE Vol. 4364, p. 290-301, Unmanned Ground Vehicle Technology III, Grant R. Gerhart; Chuck M. Shoemaker; Eds.]        